For example, Japanese Patent Laying-Open No. 2007-245295 (Patent Document 1) discloses a drill having a main body portion to and from which an insert is attachable and detachable. An insertion hole is provided in the main body portion of the drill and a clamp screw is disposed in the insertion hole. By fastening the clamp screw, the clamp screw is brought into abutment with a shank portion of the insert, whereby the insert is fixed to the main body portion.
Moreover, a holder of a drill described in Japanese Patent Laying-Open No. 2005-144655 (Patent Document 2) is provided with: a shank hole into which an insert is insertable; and a bolt hole communicating with the shank hole. The bolt hole extends in a direction inclined relative to the extending direction of the shank hole. A fastening bolt is disposed in the bolt hole and is brought into abutment with an inclined groove of the insert, whereby the insert is fixed to the holder.
Further, Japanese Patent Laying-Open No. 2011-5632 (Patent Document 3) discloses a rotary tool including: a base provided with a center hole; a loose top having a pin; and a radial screw. The pin of the loose top is inserted into the center hole. The loose top is locked in the axial direction by the radial screw.
Furthermore, WO2014/103972 (Patent Document 4) discloses a drill including: a cutting tip having a shaft foot; a holder provided with a shaft receiving hole and a through hole; and a fixing member. The shaft foot of the cutting tip is inserted in the shaft receiving hole of the holder. The fixing member is inserted in the through hole and is in contact with the shaft foot.